Redstone

Redstone ore can be found deep underground (in the bottom sixteen blocks of the minecraft world) and will drop 4-5 redstone dust with an iron or diamond pickaxe and 5-6 with an enchanted 'Fortune III' pickaxe. The ore glows upon contact, and can be mined as a block with the 'Silk Touch' enchantment.

When placed on the ground, redstone dust will become redstone wire which can be used to transfer power from a redstone torch or a switch such as a Lever or Button. This can be used to activate items such as Doors, Pistons, Note blocks, rails, or a handy trap.

The power provided by a redstone device will die out after current has passed along 15 blocks of wire. In order to make longer circuits, a Redstone Repeater can be used to renew the current and continue the circuit.

Redstone can also be used to craft several devices that can be used in circuits, such as a redstone torch or pistons. Redstone can also be crafted with four iron ingots -

to create a Compass. If you have some knowledge of how circuitry works in real life, then you may have an advantage in redstone mechanics, even though redstone works slightly differently. The image below is a little guide to making some of the different components used in making huge machines and other devices in minecraft. In essence, the idea of redstone engineering is to achieve an output - such as a series of pistons being activated to reveal a hidden door - from an input such as pressing a button.

As it is mentioned above, the signal of redstone stops after 15 blocks and before the repeater was added into minecraft in the 1.3 update. People had to use Double NOT Gates to make the signal go further.

RS NOR Latch

A device where Q will stay on forever after input is received by S. Q can be turned off again by a signal received by R.

This is probably the smallest memory device that is possible to make in Minecraft. Note that Q means the opposite of Q, e.g. when Q is on, Q is off and vice-versa. This means that in certain cases, you can get rid of a NOT gate by simply picking the Q output instead of putting a NOT gate after the Q output.

A very basic example of use would be making an alarm system in which a warning light would stay turned on after a Pressure plate is pressed, until a reset button is hit

AND Gate

The AND Gate is a device that have the property that you have to activate both inputs to give a signal to the output.

NAND Gate

The NAND Gate is the same as the AND Gate, but when both inputs are activated, the output is off.

RS NAND Latch (memory cell)

The RS NAND Latch is basically just a RS NOR Latch with inverters applied to the inputs and outputs.

OR Gate

An OR Gate is a device that activates the output when at least one of the inputs are activated.

NOR Gate

A NOR Gate is a device which turns the outputs off if at least one of the inputs are activated.

XOR Gate

An XOR Gate is a device that activates the outputs when the inputs are not the same.

XNOR Gate

An XNOR Gate is a device that activates the outputs only if the inputs are equal to each other.

Rapid Pulser

5-Clock

Both the rapid pulser and the 5-Clock are pulsating clocks the make the output flicker and that can be used, such as a flickering light in an alleyway or a door that repeatedly opens and closes.

Redstone has many uses and applications beyond these more rudimentary devices; with sufficient understanding of the mechanics, you can construct a huge variety of devices - from elevators to music sequencers. The important thing is to keep experimenting - with enough work, anyone can be good at redstone engineering.